The red palm weevil, Rhynchophorus ferrugineus Olivier (Coleoptera: Curculionidae), is an economically important pest of palms worldwide. To better understand the phenology of R. ferrugineus populations in the Mediterranean basin, the objective of the present work has been to estimate the effect of temperatures within the range 10–25°C on the reproductive parameters of R. ferrugineus and to determine its lower temperature thresholds for oviposition and egg hatching. Our results confirm that oviposition in R. ferrugineus is strongly affected by temperature. Lower thresholds for oviposition and egg hatching (15.45° and 13.95°C, respectively) are below the mean monthly temperatures registered in winter in most of the northern shore of the Mediterranean basin. Under these circumstances, new palm infestations would be difficult during most of the winter. These results should be taken into account when planning some palm management practices, such as pruning or pesticide treatments, in areas under a Mediterranean climate.

The southern fiddler ray, Trygonorrhina fasciata (Rhinobatidae), is parasitized by 3 monogenean (platyhelminth) species from 3 families on 3 different sites of the host: Calicotyle australis (Monocotylidae) from the cloaca, Pseudoleptobothrium aptychotremae (Microbothriidae) from the skin and Branchotenthes octohamatus (Hexabothriidae) from the gills. Cues that promote egg hatching were investigated for each species and the behaviour of their larvae was also documented. Eggs were laid by parasites in vivo and maintained at 22 °C. Three different egg hatching and host finding strategies were discovered. Calicotyle australis eggs hatched spontaneously with a strong diurnal rhythm that is likely to be under circadian control. The larva is ciliated, photo-responsive and can survive for up to 24 h at 22 °C after hatching. Pseudoleptobothrium aptychotremae may have a ‘bet-hedging’ strategy. Some eggs hatched spontaneously and rhythmically. However, since the hatching success was low, it is possible that other eggs require a different cue provided by the host. The larva is also ciliated but shows no photo-response and was observed to remain active for <4 h at 22 °C after hatching. Branchotenthes octohamatus has a ‘sit-and-wait’ strategy that depends on mechanical disturbance to stimulate hatching. The larva is unciliated, shows no photo-response but may survive for more than 2 days at 22 °C after hatching. The implications of hatching strategy, larval behaviour and morphology in the goal to find a host are discussed for each species.

Eggs of Neoheterocotyle rhinobatidis, Troglocephalus rhinobatidis and Merizocotyle icopae (Monogenea: Monocotylidae) from the shovelnose ray Rhinobatos typus (Rhinobatidae) have a distinct hatching pattern linked to light periodicity. Larvae of these 3 monogenean species emerge only during daylight when exposed to natural illumination or when incubated in alternating 12 h periods of light and dark (light on 06.00 h, light off 18.00 h). N. rhinobatidis larvae emerge with a distinct peak during the first 2 h of light; this peak is not as pronounced in T. rhinobatidis or M. icopae. Eggs of N. rhinobatidis incubated in a reverse light/dark cycle (light on 18.00 h, light off 06.00 h) hatched only during periods of illumination, again with a peak during the first 2 h of light. Evidence suggests that the hatching patterns observed in all 3 species represent true circadian rhythms because eggs incubated in 24 h light or 24 h dark conditions continued to hatch with a rhythm. Shadows, disturbance and host tissue did not promote hatching in N. rhinobatidis or T. rhinobatidis but there were indications that host tissue may promote hatching in M. icopae. The hatching patterns observed are discussed with respect to their adaptive responses to host behaviour and predation pressure.

Discocotyle sagittata displays a clearly defined nocturnal egg-hatching rhythm. When eggs of D. sagittata were incubated in alternating 12 h periods of light and darkness at 13 °C, the majority of larvae hatched within the first 2 h of darkness. Larvae were rarely recovered after 4 h of darkness, and none hatched in the light. Reversal of the light/dark cycle resulted in immediate reversal of the hatching rhythm, so that larvae emerged at the beginning of the new dark period. This suggests that hatching is a direct response to exogenous cues and not endogenously driven. In continuous darkness hatching was arrhythmic; hatching occurred in continuous light although total numbers of larvae emerging were suppressed. Field experiments confirmed that eggs exposed to the natural day/night cycle throughout development also demonstrated the precise hatching rhythm seen under controlled conditions. Mechanical disturbance played no part as a hatching stimulus. However, larvae hatched in the presence of both host mucus and gill tissue. D. sagittata does not show an egg-laying rhythm. The hatching responses have adaptive advantage related to the host's activity pattern. Trout are generally visual predators, inactive in darkness, providing a stationary target for emerging larvae responding either to darkness or to host hatching factors.

Entomological investigations in Dubai showed that, irrespective of whether they had been fed on water or 10% sugar solution, about 47% of Aedes caspius females matured eggs autogenously during their first ovarian cycle. Several blood-fed females were trapped in cages, and precipitin tests showed that some had fed on birds and camels as well as man.

Absence of autogeny combined with an examination of male terminalia showed that adults of the Culex pipiens complex were in fact Culex quinquefasciatus. The population was unusual because females were not inseminated when kept in cages, and appeared only weakly anthropophagie. CDC light traps and out of door resting cages proved useful in sampling adults. Precipitin tests showed 31.7% to have fed on birds, 7.9% on camels and only 3.2% on humans.

The number of eggs matured by Ae. caspius and Cx. quinquefasciatus were determined, and studies were made on the hatching pattern of Ae. caspius eggs. Larval habitats of Ae. caspius were unusual in having high concentrations of calcium chloride. Breeding places of Cx. quinquefasciatus comprised very polluted waters. Collections of the immature stages allowed the construction of stage-specific age-frequency histograms for both species, and survivorship curves to be plotted.