Macrosiagon nasuta (Thunberg, 1784)

Batelka, Jan & Hoehn, Patrick, 2007, Report on the host associations of the genus Macrosiagon (Coleoptera: Ripiphoridae) in Sulawesi (Indonesia), Acta Entomologica Musei Nationalis Pragae 47, pp. 143-152 : 146-147

Macrosiagon nasuta (Thunberg, 1784)

Material examined. Host species Rhynchium haemorrhoidale ( Vespidae : Eumeninae ) for all following reared specimens:April, E1U2, 1, 6; April, E2U3, 1, 8; April, F4I4, 1, 18;April, E1U, 1, 19; April, F1C3, 1, 41;April, F4I1, 1, 47; April, F4I4, 1, 97; April, E1U8, 1, 98; April, E1U4, 2, 105; April, E3I2, 1, 137; April, F4I3, 1, 179; April, F1U6, 1, 196; April, F4U2, 1, 222; April, E1I4, 1, 235; April, D2U3, 1, 284; April, F1U7, 1, 349; April, F4U2, 1, 197; Dec, E2I4, 2, 256; Dec, F2C2, 1, 133; Dec, F4U1, 1, 173; Dec, D3I3, 1, 179; Dec, D4U1, 1, 230; Dec, D2C3, 1, 407; Dec, E2I4, 1, 479; Dec, F4U5, 1, 10; Dec, F4U3, 1, 200; Feb, F1U6, 1, 128; Feb, F1U6, 1, 147; Feb, E1U6, 1, 359; Feb, E3I3, 1, 403; Feb, E4U8, 1, 487; Feb, E3U4, 1, 801; Feb, E1U7, 1, 839; Feb, F4U2, 1, 856; Feb, F2U8, 1, 859; Feb, F1U2, 1, 71; Jan, E1U1, 1, 59; Jan, D5U7, 1, 76; Jan, D4U7, 1, 326; Jan, D4U5, 1, 345; Jan, E3U4, 1, 381; Jan, F4U7, 1, 481; Jan, F4U5, 1, 504; Jan, D4U4, 1, 561; Jan, E1U5, 1, 584; Jan, E2C1, 1, 612; Jan, D4U4, 1, 656; Jan, E1I4, 1, 674; Jan, F4U7, 1, 731; July, F4I4, 1, 65; July, F1U8, 1, 71; July, F1U6, 1, 82; July, F1C3, 1, 89; July, E3U6, 1, 119; July, E3U6, 2, 120; July, D3C1, 1, 194; Jun, D2U7, 1, 93; Jun, F1U4, 1, 115; Jun, D3U6, 1, 129; Jun, F1U2, 1, 148; Jun, F1U4, 1, 164; Jun, F1C2, 1, 172; Jun, F4C2, 1, 269; Jun, F4C1, 1, 278; Jun, F4U3, 1, 281;Jun, F4I2, 1, 296; May, F4C1, 2, 4; May, F4I4, 1, 33; May, D4U6, 1, 35; May, E1U1, 3, 59; May, D2U6, 1, 99; May, D2U7, 1, 116; May, E2U5, 1, 133; May, D2U7, 1, 136; March, E2I4, 1, 3; March, E2U3, 1, 64; March, E2U7, 1, 66; March, D2U2, 1, 128; March, E4I1, 1, 217; March, E4I1, 1, 230; March, E4U1, 1, 237; March, E3U4, 1, 245; March, E3U7, 1, 255; March, E3U7, 1, 257; March, E3U8, 1, 258; March, E3U8, 1, 265; March, E3U7, 1, 280; March, E3U7, 1, 281; March, E1U5, 2, 288; March, E1U8, 1, 293; March, E1U8, 1, 294; March, E1U8, 1, 295; March, E1U8, 1, 301; March, E1U8, 1, 302; March, F1U7, 1, 381; March, F1U6, 1, 396; March, F4C3, 1, 420; March,F4U3, 1, 440; March, F4U3, 2, 450; March, D4U7, 1, 527; March, E3U8, 1, 612; March, F2U7, 1, 630; March, E3U8, 1, 656; March, F4I3, 1, 679; March, F1U6, 1, 696; March, F4I3, 2, 708; March, F3U8, 1, 724; March, F4U5, 1, 765; March, F4U5, 1, 769; March, F3U6, 1, 779; March, D5U4, 1, 789; Nov, D5C3, 1, 148; Nov, E4U1, 1, 316; Nov, F3U2, 1, 405; Nov, F3U1, 1, 483; Nov, D3C2, 1, 488; Nov, F3U2, 1, 503; Nov, F3U3, 1, 585; Nov, D3C2, 1, NA; Nov, D3I3, 1, NA; Nov, F4U6, 1, 346; Oct, D2C1, 1, 6; Oct, D2C1, 1, 7; Oct, D2C1, 1, 9; Oct, D2C1, 1, 12; Oct, D2C1, 2, 13; Oct, E1U1, 1, 37; Oct, E1U1, 1, 43; Oct, E1I4, 1, 46; Oct, E2U6, 1, 71; Oct, E2U1, 1, 79; Oct, E1I4, 1, NA; Sept, D3U6, 1, 28; Sept, E4U6, 1, 125; Sept, E4U3, 1, 139; Sept, E1I4, 1, NA ( JBCP, PHCG, IPBC; host species PHCG). Parasitism rate was 1.97 % (7,397 individuals (nests) of this eumenid were examined, 146 of which were infested by M. nasuta ). Host species Epsilon manifestatum crassipunctatum ( Vespidae : Eumeninae ): April, D3U3, 1, 136; March, F3U5, 1, 164 ( PHCG, IPBC; host species PHCG).

Observations. Infested nests of the most abundant host Rhynchium haemorrhoidale had on average 1.93 ± 0.076 breeding cells, 1.07 ± 0.024 of which were parasitized by M. nasuta . Two subspecies of R. haemorrhoidale ( R. h. haemorrhoidale and R. h. umeroater Gusenleitner, 1991) were present together in the research area, and it is not possible to identify the host precisely because no adult wasps were present in the infested nests. Additionally, three nests of R. haemorrhoidale were infested each with three individuals of the parasitoid Chrysis (angolensis group) sp., three with Chrysis (smaragdula group) sp. 1 and one with Chrysis (smaragdula group) sp. 2 ( Hymenoptera : Chrysididae ) and one individual from the family Trigonalidae (Hymenoptera) . Macrosiagon nasuta further infested two nests of Epsilon manifestatum crassipunctatum (Gusenleitner, 1991) with one individual each.

Macrosiagon nasuta made small holes in the partition walls to get out of the nest, with the dead host larvae remaining in the infested cell. Macrosiagon nasuta usually hatched earlier than the remaining host individuals, perhaps to avoid contact with R. haemorrhoidale in the nest. Nevertheless, we did not observe aggressive behaviour of the host against the parasitoid when both met in the glass tube.

In the field we observed M. nasuta many times on the inflorescences of the invasive plant species Hyptis capitata (Jacq.) (Lamiaceae) . This native of Central America is common in disturbed areas. Interestingly, H. capitata seems to be highly attractive to R. haemorrhoidale and E. manifestatum crassipunctatum due to the high nectar supply of the plant. Popularity of this plant among eumenid wasps has been observed e.g. by KELLER & ARMBRUSTER (1989) in Panama, Central America. IWATA (1975; fide ITINO 1986, p. 192) assumes that the ‘ripiphorid beetle, Macrosiagon nasutum [sic!] Thunberg may probably lay many eggs in flowers ... and ... that the hatched beetle larvae are transported into the wasp nest attaching themselves to the host wasp when the wasp visits on flowers’. Thus it is likely that the triungulin larvae of the parasitoid and the host make contact in the inflorescences. However, as the plant is an invasive species, its presence might alter the interaction between the two insects and favour higher parasitism rate of the parasitoid.

Remarks. Macrosiagon nasuta was first recorded from Sulawesi by a single specimen three years ago ( BATELKA 2004). This study provides confirmation of its occurrence on the island. Rhynchium haemorrhoidale had previously been known as a host species of M. nasuta only in Japan (see Conclusions). Epsilon manifestatum crassipunctatum is a new host record for this ripiphorid.

Distribution. Macrosiagon nasuta is widely distributed in Southeast Asia: China, Indonesia (Borneo, Sumatra, Sulawesi), Japan, Korean Peninsula, Nicobar Islands, Philippines, and Taiwan ( BATELKA 2004).