Some Observations on Various Insects the Miami Area

BUTCHER: INSECTS ON ORNAMENTALS 251 night nature really cracks down, the cold mass such as the Mangosteen and the Durian are has completely crowded out the warm air, the too tender, as they shed their leaves at about temperatures in nearly all sections of Central 60° and we have too many nights that reach and South Florida are about the same. that temperature, or lower, every winter. In considering the practicability of raising Growing some of these more tender trees in in Florida some of the more tender tropical dooryards is a difficult proposition as the fruits, it may be well to compare Florida to owner would not want to nurse his tree a the equator. The practical difference between couple of nights or occasionally four or five the two sections means that Floridians have nights a year to protect it, whereas, as a to fire on an average of about twice a year commercial crop, where they are planted in to save the most of these fruits. Californians orchards, it is not too difficult nor too expen have to fire much more frequently to save sive compared with the high value of the fruit their oranges. A very few of the choice fruits, produced. SOME OBSERVATIONS ON VARIOUS INSECTS FOUND ON FRUIT AND ORNAMENTALS IN THE MIAMI AREA F. Gray Butcher Other species of this genus attack avocado seeds in various tropical countries, according University of Miami to Barber. However, the larvae of this beetle Coral Gables develop as typical wood borers in the cambium of the trunk of the trees near the soil line. While the whole of Florida is generally de The adult beetles feed upon terminal twig scribed as "a low-lying sub-tropical peninsula" growth, and to a lesser extent upon young (Norton), southern Florida "is distinct from foliage and fruit. (See Fig. 1). the rest of the (southeastern) region in cli mate and vegetation" (Lindgren, et al). This south Florida region, exemplified by the Miami area, abounds in a wide variety of various fruit and ornamental plants not commonly found elsewhere in the United States. The dif ferent insect forms common to these various plants have not been extensively studied in the area, so the following observations and re ports on various forms are of interest as pre liminary recordings incidental to more exten sive and complete studies. Of the different fruits common in this area, avocados, mangos, guavas and papayas have had some appreciable commercial production. Other fruits such as lychees, barbados cherries and sapotes have been produced largely as yard or specimen trees with minor exceptions. Accordingly, it is only natural that the com Fig. 1.—The Avocado Twig Girdler, Heilipus squamosis mon insect pests of the first-named group of Lee. upper, the adult beetle; center, egg within an fruit trees have been reported rather ade avocado twig ; lower, feeding scars of adult beetle on avocado twig. quately, while those of the last-named group remain less commonly recognized. Adult Heilipus beetles collected late in Sep Insects on Fruit-Bearing Plants tember, 1950 from local avocado groves were On avocado trees, an insect of considerable placed in screened cages containing avocado local interest is the Avocado Tree Girdler, twigs. From beetles caged on Sept. 28, eggs Heilipus squamosis Lee. (Wolfenbarger). were found in the twigs on October 3. The 252 FLORIDA STATE HORTICULTURAL SOCIETY, 1951 eggs were almost or completely buried in the Late in June, 1951, some of our mango surface of the twig- within small areas gouged nursery stock suffered from a heavy infes out by the adult beetle. The first eggs from tation of leaf-hoppers. Their feeding on the this group hatched on October 12, and the re succulent new flush of growth produced a con mainder were hatched by noon October 13. spicuous injury, characterized by a severe In another cage, eggs deposited on October 3 wrinkling and stunting of the foliage. These hatched on October 17. Thus the incubation leaf-hoppers have been identified as Empoasca period for these eggs varied from 9 to 14 days fabae Harris, the potato leafhopper, by Dr. at normal laboratory temperatures. R. H. Beamer, University of Kansas, with the Development of the larvae of this insect cbservation that these specimens "are not quite has not been observed in detail. However, typical." This species has not previously been the length of time required from egg to adult reported on mango according to Poos and emergence is indicated from the following ob Wheeler, and other available literature. servations. Three adult beetles collected May Various insects attack guava leaves and 26 were caged with a young avocado plant. fruit, and usually require control procedures Light feeding and oviposition scars were ob under commercial production of this fruit. served intermittently until June 7, after which One of the most injurious and persistent forms date the beetles died. The caged plant was re encountered in our area is a small lepidoteran tained and watered until October 7, when it leaf-tier, identified by Mr. J. F. Gates Clark, appeared to be completely dead. On November of the U. S. National Museum, as a species of 10, a single adult beetle was observed within the genus Strepsicrates. He notes that the the cage with complete bright scales charac specimens forwarded to him may "represent a teristic of new emergence. This is an interval tropical American species that has not previ of 194 days, or slightly more than six months. ously been identified from Florida." Wolcott Similarly, a young larva taken from an reports S. smithiana Walker as common on the avocado tree on October 2 was placed in a tender leaves of guava in Puerto Rico, where portion of an avocado twig about one-half inch "the little green caterpillar . folds over in diameter. Extensive feeding within the and webs together with silk a portion of a twig required periodic replacement of fresh leaf or several smaller leaves." The feeding avocado twig cuttings, until on February 4 activities of these small caterpillars also cause an adult beetle emerged. This interval from irregular holes in the leaves, which become a young larva to adult emergence is 125 days. quite conspicuous as the leaves open out and Thus it would seem from these experiences become mature. Walker refers to an unidenti that this insect normally completes two broods fied leaf roller which could well be this form, per year. and indicates that in addition to leaf injury, Mango trees are commonly attacked by sev this form may "contribute to excessive drop eral different insect pests. During: the past ping of small fruit." Our observations would two seasons our very young seedlings and support this suggestion. some of the first flush of growth from budded Lychee trees at the University Experimen stock have been very heavily infested by tal Farm have developed minor infestations aphids, identified by Dr. A. N. Tissot, of the of various insect forms. Light infestations of University of Florida, as Aphis gossypii an undetermined soft scale have been noted Glover. In each case, the infestation developed on a few trees, but have not required control very rapidly from winged migrants, but were procedures. An armored scale, determined by confined to the very succulent new plant G. B. Merrill of the State Plant Board as the growth. Under these circumstances, severe white peach scale, Pseudaulacaspis pentagona damage was avoided only by prompt applica (Targ.), developed on young1 potted plants tion of an aphicide. Excellent control, near late this summer, and caused serious defolia 100%, was obtained with a parathion spray, tion on the more heavily infested plants. It using 1 lb. of 15% wettable powder per 100 has been readily controlled with parathion. gallons of water, with no phytotoxicity evi Our most serious lychee pest has been a red dent. With the spray applied at 10:00 a.m., spider mite, which developed in February of live aphids were hard to find by 4:00 p.m. the this year. This form caused a severe leaf- same day. russetting characteristic of the feeding injury BUTCHER: INSECTS ON ORNAMENTALS 253 of this group. Specimens were submitted to of different hosts along the east coast and Dr. A. Earl Pritchard of the University of the Keys. However, in our area, I have not California for identification. He reported that observed this scale on any other plants, and is was not the lychee mite Pardtetranychus apparently it has not spread to any other hawaiiensis, recently described by McGregor nearby hosts during the past year from this (1950), but appeared entirely distinct and localized infestation. This form is quite quite similar to an un-named form found on striking in appearance, in this instance oc Melaleuca trees. curring almost exclusively on under-leaf sur Before these mites became serious enough faces and along smaller twigs. The ovisac to warrant general control procedures, a very is quite elongate and curved, with parallel small coccinellid predator appeared and rather sides and longitudinal ridges, and is con quickly controlled them. Dr. E. A. Chapin of spicuously white colored. (Fig. 2). the U. S. National Museum identified these beetles as Stethorus utilis (Horn), a species previously reported as feeding on citrus aphids (Quayle). On barbados cherry (Malpighia glabra L.) £* caterpillar feeding within webbed leaves caused considerable injury last spring. The adult butterflies reared from these cater pillars were identified by W. D. Field of the U. S. National Museum as Ephyriades brunnea floridensis Bell and Comstock, a skipper of the sub family Pyrginae (Hesperiidae) not reported as an economic form in available en tomological literature.

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