Biology ofOmaspides pallidipennisBoheman, 1854 (Coleoptera: Chrysomelidae: Cassidinae)

Abstract

The biology and the feeding habits of the subsocial speciesOmaspides pallidipenniswere studied at the Floresta Nacional de Passa Quatro, MG, Brazil, during the period from October 2010 to April 2011. The species was bivoltine, beginning its reproductive and food cycle in October (spring) and seeking its diapause sites in April (autumn). The juveniles took 54.4 days on average to complete their development, a period in which the female remained close to offspring, only feeding during the larval stage of the juveniles. It is a monophagous species, feeding only onIpomoea albaLinnaeus (Convolvulaceae). In the first cycle, the average number of eggs was55.7±15.5eggs per egg cluster (n=1,837 eggs in 33 clusters) and in the second it was61.6±14.2eggs per egg cluster (n=5,607 eggs in 91 clusters). Oviposition peaks were observed in the months of November and February. The average durations of the incubation period and the larval and the pupal development in the first cycle were19.2±1.4;26.0±1.5;8.7±0.8days, respectively. In the second cycle they wrere16.7±1.4;27.0±2.4;10.2±1.5days, respectively.

Extreme convergence in egg-laying strategy across insect orders

“…Concentrated egg-deposition in form of an ootheca is unique and highly unusual for stick insects. In contrast, ootheca formation is a defining groundplan feature of the Dictyoptera (cockroaches, termites and praying mantises) 19 20 21 , but is also found in various other insect groups such as grasshoppers and locusts (Orthoptera: Caelifera) 19 22 23 , heelwalkers (Mantophasmatodea) 24 25 and even some chrysomelid beetles (Coleoptera: Cassidinae) 19 26 . Oothecae, also referred to as egg pods or egg cases, likely evolved to protect the eggs from desiccation, predators and parasitoids 19 20 23 25 .…”

“…The reported stick-insect ootheca is most reminiscent of those found in praying mantises (Mantodea) or tortoise beetles (Cassidinae) whose eggs do not bear a operculum, but who also build the egg case externally upon certain substrate, e.g. against plant parts or rocky underground, including external application of coating during and after highly ordered egg placement 19 20 26 .…”

Testing environmental correlates of clines in clades: an example from cassidine beetles

“…It is also conceivable that other factors related to population biology might be playing a role in this phenomenon. Unfortunately, relatively little is known about population biology of cassidines across latitudinal gradients, although some aspects of population biology in the group are documented: regarding life cycle, population abundance correlates with host plants utilisation (see Nogueira-De-S a & Vasconcellos-Neto, 2003;Gomes et al, 2012). At this point it is hard to ascribe the causes of the patterns in this clade, but work is currently underway to explore the possible roles of these and other factors; more information about the natural history of this group would be invaluable.…”

Preemptive Circular Defence of Immature Insects: Definition and Occurrences of Cycloalexy Revisited

“…This is true for larvae of Perga sp. (Hymenoptera: Tenthredinoidea: Pergidae) (Figure 3(a)), Omaspides tricolorata (Boheman, 1854) [39], and this arrangement is retained in the pupae of Omaspides pallidipennis (Boheman, 1854) (Chrysomelidae: Cassidinae) [37]. For owlfly larvae, heads form the periphery at the bottom of the aggregation and abdomens are at the periphery on top, but unlike Cassidinae or Coelomera larvae, their abdomens are more vulnerable.…”