Alfalfa Survey 2014 Summary

ACIDF Project 2014F062R

Scott Meers & Heather Leibel Methods

From 148 fields in Alberta, 30 alfalfa stems were pattern. Because of the overabundance of insects collected and mines from leaf miners were counted collected and time constraints, only one quarter of the and photographed. The stem length and number of total insects at each site were identified, vialed, and leaves of 10 of each 30 stems was also measured. The tabulated. Insects were identified to order, and in location and abundance of mines in alfalfa leaves some cases further (i.e. alfalfa weevils from other were mapped, and correlation was tested between weevils, leafhoppers from spittlebugs, lygus from abundance of mines and stem length, number of other plant bugs, grasshoppers from katydids, wasps leaves, field size, and percentage of alfalfa. from bees, etc.). The results were graphed by region and mapped by location and abundance. From 150 fields in Alberta, 100 sweeps were collected using a sweep net and 180° sweeping

We also vialled and recorded blister beetles, damselflies, stink bugs, and other interesting insects.

Table 1. A full list of the insects vialled and recorded: Diptera (flies) Hymenoptera Orthoptera Lepidoptera Neuroptera Thysanoptera Syrphid Bees Grasshoppers Adults Lacewing adults Thrips Leafminer Wasps Katydids Caterpillars Lacewing larvae Other Sawfly larvae Crickets Fly larvae

Hemiptera suborders Coleoptera (beetles) Heteroptera (bugs) Auchenorrhyncha Sternorrhyncha Alfalfa weevil adults Lygus adults Leafhopper adults Pea aphid Sitona weevil adults Lygus nymphs Leafhopper nymphs Alfalfa aphid Weevil larvae Alfalfa plant bug adults Spittle bug adults Other aphids Ladybird Alfalfa plant bug nymphs Spittle bug nymphs Parasitized aphids Ladybird larvae Minute pirate bug adult Other Minute pirate bug nymph Black grass bug adult Nabids Twice-stabbed stink bug Other

Non-insects Collembola Arachnida Springtails Spiders Opiliones (Harvestmen) Mites

Table 2. The number of fields sampled for stems and for sweeps by region Region Fields with stems sampled Fields swept Central 28 28 Northeast 26 26 Northwest 27 26 Peace 29 30 South 38 40

Results and Conclusions

Leafminer and stems Maps of mine location and abundance show a higher density in the Northwest and Peace regions of Alberta.

A large version of the leaf miner locations in Alberta

The Northwest and Peace have higher average number of mines than other regions.

100 80 60 40 20 0 average # mines in 30 stems 30 in mines # average Region

Sample photos from each region:

Most of the mines we collected had a thin tail and alfalfa blotch leafminer (same genus as Agromyza large blotch towards the apex of the leaflet (for frontella the alfalfa blotch miner), and is a very example the mines from Newell). This is consistent common species in Europe (and apparently here, with the leafminer fly Agromyza nana the lesser too).

Online keys for leaf miners according to the mine Very few of the mines did not end in a big blotch, but phenology: instead had a longer more convoluted corridor, so I For miners of Medicago (alfalfa) in Europe (scroll included photos of almost every incident of this type. down for English): These mines are likely caused by Agromyza frontella, http://www.bladmineerders.nl/plantenf/pffabaceae/m the alfalfa blotch miner. However, these thinner and edicago.htm longer mines can be confused with the serpentine For miners of Medicago in the UK with pictures: leafminer Liriomyza spp. (which is a bright yellow http://www.ukflymines.co.uk/Keys/TRIFOLIUM.php and black fly similar in size and shape to the completely black alfalfa blotch miner – and there There is a positive relationship between the number were lots of flies like this in the sweeps). Next year of mines and stem length, the number of mines and we will rear out some of these mines to the adult flies number of leaves, and the number of mines and the % for identification. alfalfa in the field. However there is no relationship between the number of mines and the size of the field. 150 150 y = 0.244x - 3.2441 y = 0.0483x - 6.5642 R² = 0.0144 R² = 0.0592 100 100

50 50 # mines# in 10 stems # mines# in 10 stems 0 0 0 20 40 60 80 100 0 500 1000 1500 average stem length of 10 stems (cm) # leaves in 10 stems

500 500 y = 0.7115x - 25.314 y = -0.0554x + 42.42 400 400 R² = 0.039 R² = 0.0025 300 300 200 200 100 100

# mines# in 30 stems 0 mines# in 30 stems 0 0 20 40 60 80 100 0 100 200 300 400 % Alfalfa in field Field size (acres)

And, just for fun, longer stems do tend to have more leaves. 120 y = 0.4127x + 11.741 100 R² = 0.163 80 60 40 20 in 10 stems 0 0 20 40 60 80 100 average # leaves per stem stem per leaves # average average stem length in 10 stems (cm)

All regions were roughly at the same stage of alfalfa indication of stage. All regions were sampled growth, except for the South which was slightly between mid-June and early July, however much of shorter, assuming average stem length is an the South was sampled closer to mid-June.

average average length (cm)stem 46

44 Central Northeast Northwest Peace South Region

Sweep Results

Overall In comparing the number of insects in 25 sweeps between regions, the South has more than any other region. 900 800 700 600 500 400 300 200 100 per site insects of # total Average 0 Central Northeast Northwest Peace South

Flies Many flies are pollinators and some are even tachinid flies, laying their eggs in the larvae of other predators such as syrphid flies or parasitoids such as insects.

1.4 120

1.2 100 Syrphid fly 1 Other Diptera 80 0.8 60 0.6 40 0.4 20 Average # in ~25 sweeps ~25 in # Average 0.2 sweeps ~25 in # Average 0 0

Hymenoptera Bees, including bumblebees, leafcutter bees, pollinators. Wasps, which include various parasitoids honeybees, and others, are strong fliers and largely from the ichneumonid and braconid families to the evaded our nets, but they are found throughout very tiny chalcid wasps, are found throughout Alberta. Both bees and wasps are important Alberta. 0.35 70

0.3 60 Bees Wasps 0.25 50 0.2 40 0.15 30 0.1 20 0.05 10 Average # in ~25 sweeps ~25 in # Average Average # in ~25 sweeps ~25 in # Average 0 0

Grasshoppers and katydids Grasshoppers are found throughout Alberta but are Alberta. Most of the katydids are either slender usually not found in large numbers in alfalfa. meadow katydids, prairie meadow katydids, or Katydids seem to be only in southern and central gladiator katydids. 6

5 Grasshoppers 4 Katydid 3

Average # in ~25 sweeps ~25 in # Average 1

0 Central Northeast Northwest Peace South

Lepidoptera We saw moths, butterflies, and skippers throughout The caterpillars of European skippers feed on timothy Alberta. Most of these were non-descript small white and other grasses. moths, cabbage butterflies, and European skippers. 8 Lepidoptera adult

7 Lepidoptera larvae 6 5 4 3 2

Average # in ~25 sweeps ~25 in # Average 1 0 Central Northeast Northwest Peace South

Lacewings Lacewings, including the green lacewing commonly bodied insects such as caterpillars. The adults largely found in Alberta, are beneficial insects. The larvae feed on pollen, nectar, and honeydew, although they are voracious predators of aphids and other soft will occasionally eat aphids and mites, too.

0.35 Lacewing

0.3

0.25

0.2

0.15

0.1

Average # in ~25 sweeps ~25 in # Average 0.05

0 Central Northeast Northwest Peace South

Weevils Alfalfa weevils can be a major pest, and their range the pea leaf weevil and sweetclover weevil, which are has been advancing into Alberta from the south and species of the genus Sitona. We found Sitona weevils east in recent years. We found that the range of the throughout the growing region of Alberta. Although Alfalfa weevil remains largely in the south, but has there were weevil larvae found near Edmonton, it is encroached into central Alberta. We also looked at likely that they belonged to Sitona.

180 160

Alfalfa weevil adult 140 Weevil larva 120 Sitona spp 100 80 60

Average # in ~25 sweeps ~25 in # Average 40 20 0 Central Northeast Northwest Peace South

We also found a number of other weevils, some of punctiger, whose larvae feed on dandelion seeds. which we noticed were abundant in crops heavily These weevils belong to the same genus, and look infested with dandelion. We sent some of these to very similar, to the cabbage seedpod weevil and the Ottawa for identification which is still pending. We flixweed weevil, but can be distinguished by the suspect they are the species Ceutorhynchus distinct white spot in the center of their back.

Ladybugs The vast majority of the ladybugs we found were thirteenspot, three-banded, twospot, fivespot, sinuate, sevenspot beetles, but we also found a few other and the wee-tiny ladybird beetles. species. These included the parenthesis, expurgate, 20 18 Ladybird beetle 16 14 12 10 8 6 4 Average # in ~25 sweeps ~25 in # Average 2 0 Central Northeast Northwest Peace South

Species break down:

Lygus and Alfalfa plant bugs Nymphs of lygus and alfalfa plant bugs out- other in each region, except for the Northwest where numbered their adult forms in our survey, likely due lygus nymphs more than double the number of alfalfa to the timing of the sampling. The numbers of lygus plant bug nymphs. The alfalfa plant bug can impact and alfalfa plant bug nymphs seem to match each seed production.

45 Lygus adult

40 Lygus nymph 35 Alfalfa plant bug adult 30 Alfalfa plant bug nymph 25 20 15 10 Average # in ~25 sweeps ~25 in # Average 5 0 Central Northeast Northwest Peace South

Minute pirate bugs Minute pirate bugs are very small predators with a nymphs of aphids and leafhoppers. When prey is not distinct black and white X pattern on their back. They available they feed on pollen and plant juices. feed on spider mites as well as eggs and small

8 Minute pirate bug adult

7 Minute pirate bug nymph 6 5 4 3 2

Average # in ~25 sweeps ~25 in # Average 1 0 Central Northeast Northwest Peace South

Black grass bugs Black grass bugs feed on various native and mixed alfalfa-grass. There are many species of black introduced range grasses, and are likely abundant in grass bugs and at high populations they can be a pest. alfalfa because many of the fields we swept were 9

8 Black grass bug adult 7 6 5 4 3 2 Average # in ~25 sweeps ~25 in # Average 1 0 Central Northeast Northwest Peace South

Nabids Nabid bugs (or damsel bugs) are predators of aphids and nymphs of other insects.

8 Nabid bugs 7 6 5 4 3 2 Average # in ~25 sweeps ~25 in # Average 1 0 Central Northeast Northwest Peace South

Twice-stabbed stink bug This little black and red stink bug feeds on seeds and is not considered a pest.

2.5 Twice-stabbed stink bug

1.5

0.5 Average # in ~25 sweeps ~25 in # Average

0 Central Northeast Northwest Peace South

Mites, thrips, and springtails Mites (usually spider mites, but sometimes red velvet alfalfa. Other mites can be parasites on insects or feed mites and others), thrips, and springtails (collembola) on insect eggs or fungi. Thrips suck plant juices as are all found throughout Alberta. Spiders mites suck well, but rarely cause economic damage in alfalfa. plant juices and can be a pest in large numbers, but Springtails feed on soil microorganisms and detritus. usually a good rainfall or irrigation will wash them We found a few different types of springtails. from the plants, so they are rarely a problem for

140 Mites 120 Thrips 100 Springtails 80 60 40 20 Average # in ~25 sweeps ~25 in # Average 0 Central Northeast Northwest Peace South

Aphids Aphids are everywhere in Alberta, and pea aphids greatly outnumber other aphids in alfalfa.

120

Pea aphid 100 Alfalfa aphid 80 Other aphid 60

Average # in ~25 sweeps ~25 in # Average 20

0 Central Northeast Northwest Peace South

Spiders and Opiliones Spiders and opiliones (harvestmen or daddy-long- insects. Opiliones are omnivorous scavengers and eat legs) are found throughout Alberta. Spiders, as fungi, plant material, dead things, and sometimes everyone knows, are predators and largely eat small small insects. 14

12 Spiders 10 Opiliones 8 6 4 2 Average # in ~25 sweeps ~25 in # Average 0 Central Northeast Northwest Peace South

Leafhoppers and Spittlebugs Leafhoppers and spittlebugs are found across Alberta.

30 Spittle bug Spittle bug nymph

25 Leafhopper adults Leafhopper nymphs 20

Average # in ~25 sweeps ~25 in # Average 5

0 Central Northeast Northwest Peace South

Acknowledgements We are grateful to ACIDF for funding this project. helped collect the samples and Jan Lepp who helped We would like to thank the producers for access to with data entry. Also we greatly appreciate the work their fields and Jacob Mafro from MARA, Danika of Heather Leibel and Margo Unruh for processing Bonowicz, David Brennan, and Jennifer Todd who the massive amounts of insects found in the samples.