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Pazius cinctipes n. sp. and Issikiella amazonica n. sp. are described and illustrated. Both are compared to the most closely related species in their respective small genera. Both are from southernmost Colombia.

—Direct photooxidation of cyanine dyes was found to be markedly enhanced by formation of hypsochromically shifted (H) aggregates. Singlet oxygen was found to attack many cyanines possessing low oxidation potentials with rate constants in excess of 108 t mol-1 s-1. Singlet oxygen attack on 3,3′-diethyl-8,10-dimethylthiacarbocyanine yields carbonyl products consistent with 1,2 addition to the 2,8 bond of the methine chain.

One of the minor orders of insects, the Mecoptera comprise about 500 known extant species arranged in 32 genera and 9 families (22, 106). They have been of interest to entomologists out of proportion to their small numbers, however, because of their supposed ancestral relationship to the major orders Diptera and Lepidoptera. Certainly, Mecoptera are among the oldest neuropteroid or holometabolous insects known from the fossil record. They make up a relatively conspicuous part of the insect fauna of the Lower Permian, where the Holometabola first appear (32). The 348 species of Permian, Mesozoic, and Tertiary Mecoptera in fact show more diversity, based largely on wing venation, than modem ones and have been assigned to 87 genera in 34 families (171). Most species of Mecoptera are only rarely encountered by entomologists, and biological knowledge of them based on observations of the living insects has been scant until recent years (34). Even morphological studies of any but the more common species have been few. Purely taxonomic and taxo­ nomic-distributional accounts have made up much of the literature on the order. Kaltenbach (73) has recently summarized what is known of the Mecopt­ era, with emphasis on their morphology, histology, physiology, and behav

Although chiggers have been reared and carefully observed in the laboratory, no one has seen them in copulation. Finally, after observations by the senior author extending over 8 years, it has been found that chiggers accomplish insemination with spermatophores. This paper describes the deposition of spermatophores by the male and the behavior of the female as she is inseminated. For the past several years, structures resembling the fruiting bodies of Mucorales-like molds were noted in chigger cultures. This resemblance was, in fact, so striking that attempts were made to culture these "molds." However, certain unique features of these structures became apparent as further observations were made. Mycelial growth could never be demonstrated. These structures were never seen in tubes containing only larvae, nymphs or females. They were commonly found in tubes containing adult male chiggers and frequently they appeared in freshly prepared culture tubes within minutes after a male was introduced. These observations suggested that the stalked bodies were not of plant origin but rather depositions by male chiggers. It is important to note that definitive observations could not be made until a reliable method was found for determining the sex of living adult chiggers and until, in the case of mixed cultures, large numbers of chiggers, identified from correlated larval skins, could be reared individually to the adult stage. Further observation and experimentation have demonstrated that these structures deposited by males are in fact stalked spermatophores and that female chiggers can be inseminated by coming in contact in a suitable manner with these spermatophores. This process of insemination has been noted in other arthropods, some closely related to Trombiculidae. Lundblad (1929) reported the deposition of sessile, stalked, spermatophores in aquatic environments by males of Arrhenurus (= Arrenurus) and other hydracarine genera. Males were noted directing females into position over the spermatophores. Andr6 (1953) in observing Allothrombium, described the emission of the spermatophore by the male and the manner in which the female picked up the spermatophore. Schaller (1954) presented measurement data on spermatophores of the oribatid mite Belbc geniculosa. Spermatophores of several types have been described from a wide variety of other arthropods, including ticks, pseudoscorpions, scorpions and some insects.