Stethorus ( Stethorus ) siphonulus Kapur, 1948

Stethorus ( Stethorus) siphonulus Kapur

( Figs 17a–i View FIGURE 17 , 18a–h View FIGURE 18 )

Stethorus siphonulus Kapur, 1948: 314 .– Pang & Mao 1975: 419; Ren & Pang 1996: 319; Wang & Chen 2022: 134; Seki & Maruyama 2025: 278.

Stethorus japonicus Kamiya, 1959: 140 . Synonymized by Seki & Maruyama 2025: 278.

Stethorus aptus tsutsuii Nakane & Araki, 1959: 48 .–Sasaji 1971: 86. Synonymized by Seki & Maruyama 2025: 279.

Diagnosis. Length: 1.30–1.50 mm; width: 1.00– 1.10 mm. Form elongate oval, dorsum moderately convex, and densely pubescent ( Fig. 17a, b View FIGURE 17 ). Head black, anteriorly distinctly lighter yellowish to reddish-testaceous around clypeal margin ( Fig. 17c View FIGURE 17 ), more prominently so in males; antennae, mouthparts, and legs testaceous. Abdominal postcoxal lines shallowly semi-circular, enclosed area with punctures arranged in a single transverse row, sometimes with an additional anterior row of only a few punctures ( Fig. 17d, e View FIGURE 17 ). Male genitalia ( Fig. 17f–i View FIGURE 17 ) as illustrated.

Immature stages. Immature stages as illustrated in Fig. 18 View FIGURE 18 .

Material examined. INDIA: Tamil Nadu: Kuzhumani, N 10°83'75.95" E078°59'53.22", 25.viii.22, Ex. Tetranychid mites on Physalis sp. , R. Thanigairaj, 10 ex. (ICAR-NRCB) .

Distribution. India ( Kerala; Tamil Nadu) (new record); China; Malaysia.

Biology. This species is commonly collected in association with Tetranychus spp. found on coconut and Sesbania sp. , a fodder shrub grown as a live fence on the borders of banana plantations in many parts of South India. It is included here due to the likelihood of its occurrence on banana also. Collected on Physalis sp. , Moringa oleifera , and coconut (label data).

Notes. The Indian material fits the description of S. siphonulus given by Kapur (1948) and Seki & Maruyama (2025). Kapur (1948) described S. siphonulus based on two specimens from Malaya. The male genitalia of the specimens examined for this work also match Sasaji’s (1971) descriptions of S. aptus tsutsuii Nakane & Araki, 1959 , and S. japonicus Kamiya, 1959 . Sasaji (1971) stated S. aptus tsutsii could be a subspecies of S. japonicus . Seki & Maruyama (2025) reviewed the Japanese species of Stethorus and Parastethorus and synonymized S. japonicus and S. aptus tsutsuii with S. siphonulus . They observed that the original descriptions by Kamiya (1959) and Nakane & Araki (1959) revealed no morphological differences and the morphological features of S. japonicus were completely consistent with those of S. siphonulus based on the drawings from the original description and type specimens. Seki & Maruyama (2025) also stated that S. ( S.) siphonulus itself may be a synonym of S. ( S.) aptus Kapur (1948) , which requires further study. Kapur (1948) described S. aptus based on a female and two other specimens from China and did not illustrate the male genitalia. A reliable diagnostic account of S. aptus is not available anywhere. Kapur (1948) stated that the ‘femoral lines’ in S. aptus were “widely rounded, complete and extending to near the middle of the length of the segment”. However, in S. siphonulus , the postcoxal lines are posteriorly distinctly short of mid-length of the abdominal ventrite 1.

Comparison of the images of the final instar larvae from India with the illustrations given by Kishimoto et al. (2013) for S. japonicus also suggests that the Japanese and Indian material are conspecific as the the pronotal shield of the full-grown larva has black, punctate patterns ( Fig. 18a–c View FIGURE 18 ) as mentioned by Kishimoto et al. (2013).