A close relationship between habitat and external morphology is widespread among many animals, including reptiles. Here, I studied the relationship between abiotic environmental conditions and body size of four lacertid species (Phoenicolacerta laevis, Ophisops elegans, Acanthodactylus boskianus,andMesalina guttulata) occurring in Israel. I examined the effect of average annual temperature and average annual precipitation on body and limb dimensions, using linear statistical models. Temperature- and precipitation-related geographic clines in body size showed the same trend among all species. Females displayed stronger phenotypic response to temperature gradient than conspecific males, suggesting a sex-specific effect of natural selection. Snout-vent length (SVL) was negatively correlated with temperature, supporting Bergmann’s rule inO. elegansand in femaleP. laevisandA. boskianus, but not inM. guttulata.Precipitation was positively related to SVL inO. elegansandM. guttulata, and in femaleP. laevisandA. boskianus.The relative extremity lengths, especially hind limb segments, generally increase towards hot and dry locations, following Allen’s rule. Among the Mediterranean region species (P. laevis, O. elegans) the morphological-environmental link with temperature was stronger than in desert dwellers (A. boskianus, M. guttulata), for which precipitation was the major determinant of spatial variation.

During the active season, extending from June to October, hornets emerge from their nest in the field in all the daytime hours. In the beginning of the season, when the number of workers is relatively small, the number of exits from the nest is fairly uniform numerically throughout the day. However, with the increase in hornet population from July onwards, the number of workers emerging from the nest entrance around noon (1100-1300 h) is by 1-2 orders of magnitude greater than the number of those emerging in the morning or evening hours. This disparity persists till September or October, at which time the workers revert to behave as in the beginning of the season. It appears, therefore, that in this period hornet activities outside the nest are coordinated with the meteorological conditions, and in this regard, the highest correlation is with the ultra violet B (UVB) radiation level and to a lesser extent with the temperature. Presumably, also, the greater noon-hour activity in the nests of hornets in the field stems from the digging hornets benefiting from the greater availability of solar energy at noon, mainly that of UVB radiation. We assume that the hornets are able to utilize the UVB radiation, but what part of their body is "absorbing" the UVB energy is still a matter of further investigation.

Social wasps and hornets maintain their nest in the dark. The building of the combs by all Vespinae is always in the direction of the gravitational force of Earth, and in each cell's ceiling, at least one 'keystone' is embedded and fastened by saliva. The sensory mechanisms that enable both building of sizeable symmetrical combs and nursing of the brood in the darkness merit investigation, and the aim of the present study was to identify and characterize the 'keystones' that exist in the ceiling and in the walls of the social wasp comb cells. Bio-ferrography was used to isolate magnetic particles on slides. These slides, as well as original cells, were analyzed in an environmental scanning electron microscope by a variety of analytical tools. It was found that both the roof and the walls of each comb cell bear minerals, like ferrites, as well as Ti and Zr. The latter two elements are less abundant in the soil around the nest. Ti and Zr are known to reflect infrared (IR) light. IR imaging showed a thermoregulatory center in the dorsal thorax of the adult Oriental hornet. It is not known yet whether these insects can sense IR light.

In both the large carpenter bee (Xylocopa pubescens) and the bumblebee (Bombus terrestris), a hot spot was detected in the center of the prothorax on its dorsal-external aspect. In both cases, the temperature in this hot spot was found to be greater than the ambient temperature and that at the tip of the gaster. In B. terrestris, it was higher by 9-10 degrees C from that at the gaster tip and by 15-16 degrees C from the ambient temperature, while in X. pubescens the corresponding differences were 11-20 degrees C and 18-19 degrees C, respectively. The recorded thermal differences were not fixed but were rather variable, temporally as well as individually, but invariably all individuals measured showed these temperature differences. Furthermore, in none of the studied specimens was a hot spot detected in any part of the body other than the prothorax. From this hot spot in the prothorax, there is a cascade of temperatures in both directions, that is, anteriorly towards the head and posteriorly towards the gaster, with a graded drop in temperature in either direction. This article discusses possible reasons for the existence of such a hot spot in this particular location (the prothorax), its role or function, and its mode of operation. The authors speculate that it is a thermoregulatory center (for heating or cooling) that might be present in possibly all Hymenoptera that spend a considerable part of their life flying, regardless of whether they are social, parasocial, or solitary.

The Oriental hornet bears both brown and yellow colors on its cuticle. The brown component is contributed by the pigment melanin, which is dispersed in the brown cuticle and provides protection against insolation, while the yellow-colored part contains within pockets in the cuticle granules possessing a yellow pigment. These yellow granules (YG) are formed about 2 days prior to eclosion of the imago, and their production continues for about 3 days posteclosion. Xanthopterin is the main component of the granule and lends it its yellow color. Xanthopterin produces a characteristic excitation/emission maximum at 386/456 nm. Characterization by use of mass spectrometry showed the compound to have a molecular ion of 179, as expected from xanthopterin. Spectroscopic examination of the absorption of an entire stripe of yellow cuticle in the course of its metamorphosis revealed that the absorption steadily increases throughout the process to a maximal level of absorption about 3 days posteclosion. In the absence of the YG, the cuticle is permeable to the passage of all wavelengths within the visible range and to the UV range (290-750 nm) in all age groups of hornets. The newly ecloded hornets depart the nest to engage in activities requiring exposure to insolation only as the process of granule formation terminates, namely, when the layer of YG in the cuticle suffices to absorb all the harmful UV radiation.