Fingulus Distant

Yasunaga, Tomohide, Yamada, Kazutaka, Duangthisan, Jomsurang & Artchawakom, Taksin, 2016, Review of the plant bug genus Fingulus Distant in Indochina (Hemiptera: Heteroptera: Miridae: Deraeocorini), with descriptions of two new species, Zootaxa 4154 (5), pp. 581-588 : 582-583

Genus Fingulus Distant

Diagnosis. Recognized readily by small to moderate size (2.0−4.5 total length); usually uniformly and clearly punctate dorsum and propleuron; porrect, slender head with strongly developed, necklike postocular region; vertex usually with a narrow basal carina; broad, flattened or rarely weakly rounded pronotal collar; deep cuneal incisure sometimes marking strongly deflexed hemelytron. See Stonedahl & Cassis (1991) for further diagnostic characters.

Distribution. Known widely from Old World tropics, subtropics and warm temperate zones, including Africa, continental China, India, Indochina, Indonesia, Philippines, Taiwan, east to New Caledonia and northeastern Australia, and north to southwestern Japan archipelago (Shikoku, Kyushu and Ryukyu Islands).

Discussion. This deraeocorine genus is uniquely defined by the above diagnostic characters, especially the porrect, tapered head, which is similar in shape to some anthocorids and implies a predaceous food preference. Stonedahl & Cassis (1991) discussed the character sets in detail and posited its most closely related genus as Angerianus Distant which is particularly characterized by having the anteriorly flattened, vertical head reminiscent of the Hyaliodini (e.g., Stethoconus Flor, 1861 ; see Yasunaga et al., 1997; 2001), long, slender antennal segment I and femora, and excessively deflexed hemelytron with the membrane covering the caudal abdomen ( Fig. 2 E −F) (Stonedahl, 1991). Nonetheless, except for the porrect head, some members of Fingulus have the conventional deraeocorine shape and surface structures.

Although nothing is currently known about biology for any Angerianus species, the first author has collected quite a few specimens including some immature forms of A. fractus and A. maurus by sweeping various herbs and shrubs both in Nepal and Thailand; thus, we presume that some members of Angerianus may be polyphagous. On the other hand, Fingulus species have rather restricted habitat preferences as mentioned below for F. angkorensis , and appear to be oligophagous. Also in the Ryukyus, Japan, F. longicornis Miyamoto is known to inhabit leaf-curl galls of Ficus microcarpa induced by Gynaikothrips ficorum (Marchal) ( Thysanoptera : Tubulifera), often together with an anthocorid, Montandoniola thripodes Bergroth ( Anthocoridae : Oriini ) ( Nakatani et al., 2000; Yasunaga et al., 2001). Based on the general shape of the immature forms that appear to mimic thrips, Fingulus members possibly have particular associations with certain thysanopterans (cf. Yasunaga et al., 2015). Further surveys on biology are required to verify the relationship between Angerianus and Fingulus .

Figures

FIGURE 2. Habitus images of Fingulus spp. (A − D) and Angerianus spp. (E − F) A − B. Fingulus rubricatus, holotype male. C. F. collaris Miyamoto, female adult from Ishigaki Island, Ryukyus, Japan. D. Same, final instar nymph from Iriomote Island, Ryukyus. E. Angerianus fractus Distant, male from SERS. F. A. maurus Distant, female from SERS. Images C & D courtesy of Mr. M. Takai.