A Abafi-Aigner, Lajos (Ludwig original family name: Abafi-Aigner and changed Aigner) his German Christian name “Ludwig” to the Hungarian equivalent “Lajos.” However, despite george hangay his successes in publication and writing his busi- Narrabeen, New South Wales, Australia ness begun to decline in the 1880s and within a few years he faced financial difficulties, which Ludwig Aigner was born on the 11 February 1840 ultimately led to the closure of his famous book- at Nagyjécsa, Torontál Shire, Transylvania, Hungary, shop. Disillusioned, he discontinued most of his now Romania. His family moved to Temesvár, a business activities, and from 1890 he devoted all large town in Transylvania, where he received a his time and energy to lepidopterology. In 1895, formal education in commerce and begun his he published the results of his studies in the career as a book merchant. His family was of ethnic Természetrajzi Füzetek (Notebooks of Natural German stock and young Ludwig only learned History), the journal of the National Museum’s Hungarian when, in 1858, they moved to Pozsony Natural History Department and he was one of (now Bratislava and in the Slovak Republic), a the authors of Fauna Regni Hungariae (Catalogue large town with predominantly Hungarian inhab- of Hungary’s Fauna). He resurrected Rovartani itants. From here he soon moved on to Pest (now Lapok (Entomological Papers), which was estab- Budapest) and in 1863, as it was the custom in lished in 1884 but ceased to exist in 1886. His those years, he wandered all over Austria and treatment of the butterfly fauna of Hungary won Germany. He completed his studies in Köln and the coveted Bugát Prize. Based on this work he Stuttgart before returning to Pest. He always had published Butterflies of Hungary in 1907. The an interest in entomology and he became a keen book was (and probably still is) one of the most amateur lepidopterologist. However, besides ento- popular entomological publications in Hungary. mology, he had a great variety of other interests It has inspired countless young entomologists and too, especially in the field of publishing, writing, made the name of Abafi-Aigner well known to historical research as well as aspirations in busi- every naturalist in the country. He passed away ness. He found success in publishing and in estab- on the 19 June 1909. lishing a popular bookshop. In 1870 he was initiated as a Freemason and eventually he rose to the highest positions in the Order. For 12 years he Reference has worked on an extensive monograph of the history of Freemasonry. He used his Hungarian Horváth C (1990) A rovartan tudósa. E’ let és Tudomány pen name “Abafi” in a hyphenated form with his 45:290, 312 2 A Abaxial Surface Abaxial Surface drawings of a quality that was very high for that time. Some of the insect illustrations included The lower surface of a leaf (contrast with adaxial not only adults, but also larvae and the plants on surface). which they fed, and even observational notes. He died about 1840. Abbott, John Reference John Abbott was born in London in 1751. In Eng- land, he was given drawing lessons and, through Mallis A (1971) American entomologists. Rutgers University his drawing instructor, was introduced to Dru Press, New Brunswick, NJ, 549 pp Drury, a collector of insects who had been presi- dent of the Linnean Society. These two encoun- ters encouraged him to collect insects and draw Abbott’ s Formula them, but his father was training him to be an attorney. Finding legal paperwork not to his lik- A mathematical technique commonly used to ing, he emigrated to Virginia in 1773. After 2 assess mortality in insecticide trials when there is years in Virginia, he relocated to Georgia, where need to correct for a change (decrease) in the he served as a private in the Third Georgia Con- background population density (i.e., in the check tinental Battalion during the Revolutionary War. or control plots). The formula is: For his military service he received several hun- % corrected control = 100 × (% alive in the check % dred acres of land, and worked as a planter and alive in the treatment)/(% alive in the treatment) schoolmaster. In Virginia he had collected Amer- ican insects and bird skins, and drew and painted insects and birds. Some of the specimens and paintings were shipped to England for sale. Some Abdomen of the paintings, after sale, adorned books on birds, insects, and spiders written by various The posterior of the three main body divisions of authors, not necessarily with acknowledgment an insect (Fig. 1). to Abbott. In all, Abbott produced over 3,000 Abdomen of Hexapods Abdomen, Figure 1 Cross section of an insect abdomen, showing components of the insect circulatory system and direction of hemolymph flow (adapted from Evans, Insect biology). Abdomen of Hexapods A 3 Abdomen of Hexapods primitive, the number of abdominal segments is usually greater, as occurs in the Protura with 11 severiano f. gayubo segments (Figs. 2–5). An exception is the Collem- Universidad de Salmanca, Salamanca, Spain bola, which only possess six. In addition, it is nec- essary to keep in mind that, in certain cases, the The abdomen constitutes the caudal tagma in the total number of visible segments does not coin- hexapods and is usually larger than the other two, cide with what a particular individual actually the head and the thorax. This region is also referred possesses, since some segments remain “invisible” to as a visceral area because it houses the visceral upon being telescoped, particularly those of the organs. Its form can vary depending on the group, posterior region of the abdomen. and even on the species. The maximum number of According to Bitsch, a generalized abdominal observed segments is 11, although certain authori- segment would be limited anteriorly by a preseg- ties consider a twelfth segment that in fact corre- mentary domain, separated from the segmentary sponds to a telsonic caudal region. In general, the domain proper (of greater size) by a suture that number of segments decreases from the preimagi- begins an internal crest named the costa or antecosta. nal phases to the adult stage, especially in those This crest anteriorly delimits an acrotergite or pre- holometabolous insects in which the last segments costa in the tergal part and a presternite in the sternal of the adults are formed from imaginal discs part. In this idealized model, the muscles would be during pupation. In the groups considered most inserted in successive antecostas. No known struc- ture is homologous to the thoracic furca. The presence of the gonopore (double in Ephemeroptera) in segments VIII and IX (in VII in the case of Ephemeroptera), and fundamentally of the external structures related to reproduction (the genitalia), produce important modifications in those segments. Considering the presence of these genitalia, three regions of the abdomen are recognized: an anterior (pregenital or visceral region that includes the first eight segments), median (genital region, eighth and ninth segments), and caudal regions (postgenital region, tenth and eleventh segments plus the telsonic region). The Pregenital Region In the most generalized condition, the first abdom- inal segments conserve their basic structure, being easily distinguished from the thoracic segments. Nevertheless, the most frequent condition is that which produces morphological modifications that Abdomen of Hexapods, Figure 2 Diagram of a affect the thoracic-abdominal union. These modi- proturan (Protura) showing abdominal segments fications usually consist of reductions that affect and appendages: dorsal view (left), ventral view the sternal region and involve a greater or lesser (right). desclerotization of different structures and their 4 A Abdomen of Hexapods Abdomen of Hexapods, Figure 3 Diagram of chewing louse (Mallophaga) showing abdominal segments, including numbering of segments: dorsal view (left), ventral view (right). incorporation to the metathorax. In this sense, the modified appendages exist in Collembola. In case of the Hymenoptera, Apocrita stands out, in Archaeognatha, very developed coxites are differ- which a narrowing is produced between the sec- entiated, above which are inserted styli in a median ond and the third abdominal segments, which position and the exsertile vesicles in the most incorporate the thorax and is named the propo- internal position. deum. The rest of the abdominal segments are The styli are elongated pieces, articulated in called the gaster or metasoma. The region formed their base above the external face of the coxite. by the propodeum and the thorax constitutes the They are unisegmentary and lack muscles mesosoma. The narrowing allows a great ampli- inserted in their base, often presenting an apical tude of movements of the metasoma, which per- spine. Taking into account their position and mits stinging in the capture of prey in aculeates. In their embryonic development, the styli are con- some groups, like Formicidae and Sphecidae (Acu- sidered by the majority of authorities as vestigial leata), one or two segments of the metasoma form appendages, and more concretely as reduced a narrower zone called the petiole. telepodites. The exsertile vesicles are considered In the pregenital region, several appendicular internal coxal formations (internal coxalia of structures can be found. Thus, three pairs of highly some authorities). Abdomen of Hexapods A 5 antenna least in part, it is of appendicular origin. In this pretarsus sense, it is clear that in the Archaeognatha the tibiotarsus eye eighth and ninth segments are basically similar in femur pronotum males and females and their structures are homol- trochanter mesonotum coxa ogous to those already indicated for the pregenital precoxae metanotum segments. Taking into account this relationship, collophore the genitalia of Archaeognatha are considered tenaculum (catch) primitive, and therefore fundamental to interpret the genitalia of Pterygota. In the eighth segment of the Archaeognatha, the basal part of the appendicular structure is named first gonocoxa or gonocoxite and bears the first gonostylus; in the ninth is found the second gono- manubrium coxa with its corresponding stylus.