Lack of compensation by final instar larvae of the myrmecophilous lycaenid butterfly,Jalmenus evagoras,for the loss of nutrients to ants

Abstract Larvae and pupae of the Australian lycaenid butterfly, Jalmenus evagoras Donovan (Lepidoptera; Lycaenidae), are protected from parasites and predators by attendant ants. In return, the juveniles of J. evagoras secrete to the ants a solution containing substantial amounts of sugars and amino acids. Larvae of J. evagoras were reared from hatching until adult eclosion either with or without ants. Experiments were performed to examine whether fifth (final) instar larvae attempt to compensate for the nutrient loss to ants, by consuming more food, digesting food more efficiently, or extending development time. The presence or absence of ants had no effect on the feeding rate, efficiency of digestion or development time of fifth instar larvae. Larvae with ants converted a smaller proportion of ingested food into biomass, and consequently grew less than their counterparts without ants. Thus fifth instar larvae of J. evagoras do not appear to compensate for the nutrient loss to ants. Possible reasons for the failure to compensate are discussed.     

秦岭玄灰蝶属雄性外生殖器比较形态学研究(鳞翅目,灰蝶科)

对秦岭玄灰蝶属Tongeia 5种的雄性外生殖器进行了比较形态学研究.结果表明,不同种间的雄性外生殖器存在差异,可作为种类鉴别依据.     

Comparative study of the morphology of stridulatory organs of the Iberian lycaenid butterfly pupae (Lepidoptera)

We compared the pupal stridulatory organs of 35 species and one subspecies of Iberian Lycaenidae using scanning electron microscopy. The studied species belong to the tribes Theclini, Eumaeini, Lycaenini, and Polyommatini. Nine species do not show stridulatory organs on the pupae but all other species possess them. Stridulatory organs are formed by a stridulatory plate (pars stridens) placed on the fifth abdominal segment and a file (plectron) in the sixth abdominal segment. The plate has tubercles in the Theclini and Lycaenini, tubercles, ridges, or undulations in the Eumaenini, and tubercles, teeth, or unspecialized structures in the Polyommatini. Morphological differences can be found in the files of the different tribes, regarding the number of teeth, their form and size. Cuticular formations of the organs were studied on a surface of 2,500 µm² and the average of ridges, tubercles, and teeth was measured searching for relevant taxonomic information. Stridulatory organs were thought to be an adaptation to myrmecophily but we show that they are present both in myrmecophilous and nonmyrmecophilous species; therefore, we suggest that this trait probably did not evolve in relation with myrmecophily, but may be used to enhance relationships with ants. J. Morphol. 275:414–430, 2014. © 2013 Wiley Periodicals, Inc.     

Ants andPolyommatus icarus immatures (Lycaenidae) —sex-related developmental benefits and costs of ant attendance

Summary Third and fourth instar larvae and pupae of the facultatively myrmecophilous Palaearctic blue butterflyPolyommatus icarus showed no alteration in developmental time when reared in the presence of two species ofLasius ants. Sex differences were observed in larval growth and pupal weight, with males growing larger and faster. Sex-related differences also occurred in the costs and benefits of ant-attendance. Male pupal masses tended to be larger in individuals associated with ants, and their pupal weight loss was not enhanced by ant attendance. This positive developmental effect of myrmecophily is tentatively attributed to a stimulating influence of ants on caterpillar feeding behavior. In contrast, females associated with ants tended to lose more weight during the pupal stage. Hence there is evidence for developmental benefits, rather than costs, of myrmecophily in maleP. icarus immatures, whereas ant attendance appears to be more costly for females during the pupal stage. These findings are discussed in relation to data on other myrmecophilous lycaenid species. It is suggested that maintaining low-level myrmecophily and its related organs is a comparatively inexpensive evolutionary stable strategy among this butterfly group.